Water resources

"Water is the driving force of all nature."
(Leonardo da Vinci)

In an animal or a plant, 99 molecules in 100 are water… An organism is a pool in a stream of water along with metabolites and energy move through ecosystems.
(W.V. Macfarlane)

At any single moment, 94% of the earth’s water is found in the• oceans, 4% is in inaccessible aquifers, and 1,5% is locked up in polar ice and glaciers. This leaves about 0,5% of the earth’s water available for human use, but most of this water is hard to reach and much too costly to be of any practical value.